Amazon Aurora MySQL is being used by an ecommerce business to migrate its main application database. The firm is now doing OLTP stress testing using concurrent database connections. A database professional detected sluggish performance for several particular write operations during the first round of testing.

Examining the Amazon CloudWatch stats for the Aurora DB cluster revealed a CPU usage of 90%.

Which actions should the database professional take to determine the main cause of excessive CPU use and sluggish performance most effectively? (Select two.)

A. Enable Enhanced Monitoring at less than 30 seconds of granularity to review the operating system metrics before the next round of tests.

B. Review the VolumeBytesUsed metric in CloudWatch to see if there is a spike in write I/O.

C. Review Amazon RDS Performance Insights to identify the top SQL statements and wait events.

D. Review Amazon RDS API calls in AWS CloudTrail to identify long-running queries.

E. Enable Advance Auditing to log QUERY events in Amazon CloudWatch before the next round of tests.

A company is running Amazon RDS for MySQL for its workloads. There is downtime when AWS operating system patches are applied during the Amazon RDS-specified maintenance window.

What is the MOST cost-effective action that should be taken to avoid downtime?

A. Migrate the workloads from Amazon RDS for MySQL to Amazon DynamoDB

B. Enable cross-Region read replicas and direct read traffic to then when Amazon RDS is down

C. Enable a read replicas and direct read traffic to it when Amazon RDS is down

D. Enable an Amazon RDS for MySQL Multi-AZ configuration

A database specialist must create nightly backups of an Amazon DynamoDB table in a mission-critical workload as part of a disaster recovery strategy.

Which backup methodology should the database specialist use to MINIMIZE management overhead?

A. Install the AWS CLI on an Amazon EC2 instance. Write a CLI command that creates a backup of the DynamoDB table. Create a scheduled job or task that executes the command on a nightly basis.

B. Create an AWS Lambda function that creates a backup of the DynamoDB table. Create an Amazon CloudWatch Events rule that executes the Lambda function on a nightly basis.

C. Create a backup plan using AWS Backup, specify a backup frequency of every 24 hours, and give the plan a nightly backup window.

D. Configure DynamoDB backup and restore for an on-demand backup frequency of every 24 hours.

An worldwide gaming company's development team is experimenting with using Amazon DynamoDB to store in-game events for three mobile titles. Maximum concurrent users for the most popular game is 500,000, while the least popular game is 10,000. The typical event is 20 KB in size, while the average user session generates one event each second. Each event is assigned a millisecond time stamp and a globally unique identification.

The lead developer generated a single DynamoDB database with the following structure for the events: Partition key: game name Sort key: event identifier Local secondary index: player identifier Event time

In a small-scale development setting, the tests were successful. When the application was deployed to production, however, new events were not being added to the database, and the logs indicated DynamoDB failures with the ItemCollectionSizeLimitExceededException issue code.

Which design modification should a database professional offer to the development team?

A. Use the player identifier as the partition key. Use the event time as the sort key. Add a global secondary index with the game name as the partition key and the event time as the sort key.

B. Create two tables. Use the game name as the partition key in both tables. Use the event time as the sort key for the first table. Use the player identifier as the sort key for the second table.

C. Replace the sort key with a compound value consisting of the player identifier collated with the event time, separated by a dash. Add a local secondary index with the player identifier as the sort key.

D. Create one table for each game. Use the player identifier as the partition key. Use the event time as the sort key.

A large company is using an Amazon RDS for Oracle Multi-AZ DB instance with a Java application. As a part of its disaster recovery annual testing, the company would like to simulate an Availability Zone failure and record how the application reacts during the DB instance failover activity. The company does not want to make any code changes for this activity.

What should the company do to achieve this in the shortest amount of time?

A. Use a blue-green deployment with a complete application-level failover test

B. Use the RDS console to reboot the DB instance by choosing the option to reboot with failover

C. Use RDS fault injection queries to simulate the primary node failure

D. Add a rule to the NACL to deny all traffic on the subnets associated with a single Availability Zone